Determination of ibuprofen in human plasma by solid phase extraction and reversed-phase high-performance liquid chromatography

A new, sensitive and simple method for the rapid quantitative determination of ibuprofen in human plasma has been developed. This method involves the use of a solid phase extraction on "Baker" C-18 disposable extraction columns for sample clean-up and uses mefenamic acid as an internal standard. Separation and quantitation are performed by reversed-phase liquid chromatography using a Nucleosil C18 column and methanol-0.04 M phosphoric acid (80:20, v/v), as the mobile phase. Detection was achieved by UV-absorbance measurements at 229 nm.